bancroft



-BBANGROPT W. SELLERS.

LATES. 'l Pgltentea Peb. 7, 1.354.

nnn'n. nnsenorr ANDWM. SELLERS, or rnimnnnrnin, rnnnsrrivlinis.

a M Reeve-.M snr my, russi snellere se.

Specification forming [mrt of Lettere-Patent No. 19,491', dntodFeb-rnnry 7, 1854.

.To et! whom it mayconccm:

Be it known. .that we, EDWARD BANCRO'RT :intl WILLIAM SELLERS, ofIh iladelphie, Penn- Sylvania, lin-vc invented certeinnew and neef. i-ilmprovements in Lathes and that the fol lowing is ei'fnll, clear, entf exact 'tescripticn thereof reference being hed to the' accompanyingi rewil1gs,1nnlling part of this specificetion, in which- Y. 1

Figure 1 is enla-n, Fig. 2, en end elevation Figu, e cross vertical section taken at the line A a' of Fig. l and Fig. 4, n section taken' at the line B bl of'Fig. 2.y

Seme lettersv indicate lilse parte in all the figures. v Y f The r'st part of our invention relates to the method of varying the speed of the screw 'consists in the employment of a. series of eogwheels, connected and turning tegether, end receiving motion from the mandrel or from any other source, lenel imparting motion to the "series of wheels, inverted, and. all 'engaging the wheels of the rst series, and each wheel. of the second series being on e sepa-rete hollow arbor orsleeve', thesleeve of the first ttefl to turn on thesheft of the scremthe sleeve of the second iitted' te turn on the sleeve of the irst, and. so on throughout the ,serie-s, and. each sleeve or arbor being so formed as to re reive n, securing-pin, or its equivalent, con nected, with e disk 4or arm -on the end of the screw-shaft, so that by. simply shifting the pin or equivalent locking-instrument any one of the wheels in the serieswill be locked with. the screw-shaft to communicate the required. motion toit, while-the others are left free to turn on their appropriate bearings.

And the second part of our invention relates izo themethogl of .sustaining the serewshnft .or lender and preventing it from being strained.- ont of truc-an object much desired in this class of lathes; and this part of our invention consists in combining;` with the screw-sheftor leader 'ametul trough, whose cross-section is n segment of a. hollow cylinder, tting ,the

'adapted to turn .curetely, on t lender, a: the second, nis also provided with a sleeve-arbor, tted to turn on the sleeve of outer diameter of the thread, cndsc securellf to the freine that the said screw or leader' shall turn therein, and be snpported'by it to resist e115r lateral strain'to which it may be exposezl. Y

In the accompanying drawings, a e repre- .l

sent the usualsh'eersef the lathe, formell with vweys for the. carriage I) to slide on, thecerringe-being formed with projecting flanges c c, which extend under the. projections of the ways to "preventthe carriage from being lifted.,- .The .mandrel is mounted in the'usua-l inanner in heads or' puppets e e,- securecl to the shears et.i one end, and the rear eno. of the.

man'ilrel Vis. provided with e pinion, )inv-hiel;

engages either one of two' pinions, g It, which turn on stud-pins on c lever, e', and meshing into each other. This lever turns on the studiin j ci n series eifrig-wheels, k'l mfzn'so that, which communicates motion to the carri-age ,relatively tothe motion of the mandrel ;z an

owever the' lever maybe ribrated, the pinif, the largest of the serieel, The lever .is connectee -by e cozmecting-roti, o, withv e -rocli'- sllaft, p, placed in front' of 'the let-he, and provided within handle, g, by means of which 'the lever can be shifted. to' pnt either of the 'pin ions g or .7i in gear with the pinion-von the end of the ma'ildre The wheels ,k l ng 'n nre Veecfiiiin snecessionefless diameter, and ell fastenedeml turned together, and engnge thecogs of gl, similar enel' corresponding series, r e t u, inverted, het each independent-lsv Voi' the others. y Y

e sleeveerbor r, tted to turn freely, but ache 'enti -w of the screwsheft .or

the rst; the third, en the sleev'e'of the sec ond; and the fourth, in like manner, von the .sleeve ofthe third. y `Clfh'ere is e longitudinal hole lmresln in the.

emiv of each sleeve-arbor to receive at pleasure .a securiug-pin cr slide-bolt, y, which tits e series of holes, e, made in e.- plate', a', secured to the outer end of the screwsh aft, these holes corresponding -Wit-litho holes in the series of sleeve-whore, so that when the securing pin or bolt y is inserted in the rst of .the series nt' holes z and the hole'inthe sleeve of the wheel r this wheel will be locked withlthe shaft of the screw or leader, und'motion will be communicated from the mandrel, through the lnrgestfivheel, Ik, .of the ilrst seriesnndfthe The first engl smallest of the series, r, is on i of holes e, then the largest wheel, u, of the seel dreh'and so on with the other wheelsof the series. i

nwheels in the two series can be increased or relative motions which it may be desired to in bearings at the end where it is notthreaded, and' the threaded part and the other end are enneet the carriage with the" screw or leader, or

disconnect it. To the carriage is alsoattached smallest,'fr, of the second series, and hence the screw or leader will receive the quickest cmo tien relatively to the mandrel, the other Awheels ofthe second series turning freely; and if the pin or bolt be shifted to the .lastof the series md 4series will belcked to the shaft lof the screw orleader, and thenthe screw-will reeeivethc slowest motion relatively tothe man- The number and relative proportions of the diminished at pleasure, according to the intended capacity of the lathe and the diere'nt give to the screw or leader; and the change Vcan be made from the one to the other by simply shifting the pin or bolt from one to another ofthe series of holes,instead of shifting wheels, as heretofore practiced. f

The shaft of the screw or leader is sustained tirelywithout journals but rest and turn in asemicircular trough, madeof metal and firmly attached to the frame. The curvature ofi this trough should be such as to receive the screw and permit it to turn therein freely, but accurately, and to 'be supported thereby' throughout its wholelength agaillstall lateral strain and its own weight. l j

"The carriage is provided with a lever, c" jointed at d', .the underV face, near the forwar end, beingl formed with a semicircular groove, threaded* "o fit the thread' of the screw or leader, and the top of 1this lever is formed into acogger` sector, c', which engages the thread of a worm, f', on the end of an arbor, g', pro.- vided at its outer end with a crank-handle, It', by the turning cf which the operator can cone cap or cover, if," whose underl vsurrace is grooved to t and slide on the screw or leader and protect it, so thatchips and other foreign substances sha-ll not be'permitted to fall onto the screw and lodge in the supporting-trough. This cap or cover is'fcrmed in vtwo parts, one

on each side of the lever-nut c.

been'. employed, called sometimes conev wheels, with? one series free to turn each independently onthe shaft, which shaft is provided witha sliding spring-clutch, by sliding which any wheel -of the series can be clutchedto the shaft, leaving the others free to turn thereon; but such an arrangement' is not 'applicable to a lathe, for the reason that theinotion cannot 'be reversed, as the clutch must spring and .must be beveled on one side to avoid catching and holding two wheels in the act of shifting,-

and thereby stripping 0E the cogs. 1

-' WhatV we claim as our invention, and desirel to secure by Letters Patent, is' l.- VThe methodk of varying the mot-ions of th c mandrel and screw or leader by means of the two series of wheels, each series consisting of- Wheels of different diameters,4 and all the wheels of one series being connected and tnrnzing together, and imparting motion to all the wheels of the second series, with different def- Agrecs of velocity, substantially'as described, when this is combined with the method of locking any one of the wheels of the second` series with the .shaft of the screw orleader by having the wheels on separate sleevelarbors,

litted to turn on each othenand adaptedto receive a locking pin or bolt fitted to holes Vin a plate attached to the shaft of the screw, substantially as specified,- or any arrangement effecting the same end by means substantially the same. L

2. The manner of supporting and 'sustaining the screw'or leader by'combning therewith a trough, substantially as specified, having the Aouter. end ofthe said screw or leader without a journal, as 4set forth.

EDWARD BANCROFT. WlLLiAM SELLERS. 

